Employees of Lawrence Livermore National Laboratory have ported Sun's/Oracle's ZFS natively to Linux. Linux already had a ZFS port in userspace via FUSE, since license incompatibilities between the CDDL and GPL prevent ZFS from becoming part of the Linux kernel. This project solves the licensing issue by distributing ZFS as a separate kernel module users will have to download and build for themselves.

I wasn't saying it would catch-up, I was saying a stable filesystem, something people can rely on in a production environment as much as ext3 of ext4, but with more checksums.

Maybe not in as many places as ZFS yet, but it will be something which can be maintained by the same people that build the rest of kernel. And it can be distributed normally together with the rest of the kernel.